Concert: The performance will highlight Bach's liturgical genius

he wrote with regularity masterpieces that were keyed to the Christological cycle of the church year.

Perhaps the most amazing thing about Johann Sebastian Bach's career as an 18th-century church musician was the sheer regularity with which he churned out masterpiece after masterpiece keyed to the Christological cycle of the church year.

Week in and week out, from Pentecost to Advent, from Epiphany to Lent, Bach crafted cantatas, motets and chorales inspired by the fluid rhythms of Christian liturgy.

The staggering consistency of Bach's efforts and his influence on later composers will be saluted tomorrow evening at St. John's College when the Scholars of London sing sacred music from the 17th to the 20th century in a program titled "Bach Chorales and the Church Year."

The 8:15 p.m. concert, in Francis Scott Key Auditorium on the Annapolis campus, is free and open to the public.

The program will begin with Bach's Chorale "Schwingt freudig euch empor," written for the First Sunday of Advent.

In between, the London Scholars will make their way through Christmas, Epiphany and Lent, the latter celebration evoked by a work written for the Scholars by Spanish composer Angel Barja.

The spirit of Holy Week will come forth via one of Bach's great chorales from his "Passion According to St. John."

Sir John Stainer's hushed "God So Loved the World" captures the joy of Easter's blessings with rapt introspection, and there will be works keyed to Ascension Day, Whitsun, Corpus Christi, Trinity, All Saints and All Souls as well.

Also to be performed is "Evening Prayers" by English composer Philip Moore, who drew his text from the "Letters and Papers from Prison" by Dietrich Bonhoeffer, the Lutheran clergyman killed during Hitler's Third Reich.

Moore's music is based on Bach's Chorale "Nun komm, der Heiden Heiland," which also will be heard in tomorrow's program.

The Scholars of London is one of Britain's finest choral ensembles. It is so named because each of its founding members won a scholarship to Cambridge University to sing in the famous choir of King's College Chapel.

The Scholars of London began as an all-male ensemble in 1970, but became a mixed quartet two years later when a female voice was added to create a new sound and open the group to a wider repertoire.

David van Asch and Robin Doveton are founding members. Kym Amps and Angus Davidson joined in 1983 and 1986, respectively.